Casters are used in many industries where it is often necessary to be able to easily move a relatively heavy unit. The present invention was developed in connection with the swimming pool industry which uses removable swimming pool covers which can be reeled onto a spool which is supported at each of its ends on opposite sides of a swimming pool where it is necessary to move the rolled swimming pool cover unit to and away from a pool. When the cover is being rolled or unrolled from the spool the swimming pool cover support structure should not be mounted on casters but instead should be supported directly on the pool deck or other firm support platform in the area. In order to be commercially viable, the caster must be easy foldable from its operative position at least 180.degree. and preferably about 270.degree. to storage and it must be inexpensive to manufacture.